Lesson 9 Vital Signs

Soon after a patient arrives on the nursing unit you should
begin your nursing assessment. You should take several measurements to establish a
baseline for further observations of that patient. Among these measurements are height,
weight, and vital signs. The vital signs are the body temperature, the pulse or rate of
heartbeats, the respiration or rate of breathing, and the blood pressure. The vital signs
are abbreviated TPR and BP for temperature, pulse, respirations and blood pressure. These
readings are called vital signs because they all must be present for life to continue.

HEIGHT AND WEIGHT

The patient's height and weight are recorded on admission
for several reasons.

Diet Management. The patient's ideal weight may be
determined. The health care team will also be able to monitor weight loss or gain.

Observation of Medical Status. Taking the patient's
height and weight may indicate that the patient is overweight, underweight, or is
retaining fluids (edema). The health care team can observe changes in weight caused by
specific disease processes and determine the effectiveness of nutrition supplements
prescribed to maintain weight.

Calculation of Medication Dosages. Drug dosage is often
prescribed in relation to a patient's weight when a specific blood concentration of the
drug is desired. Larger doses may be required in a heavier person.

MEASURING HEIGHT AND WEIGHING THE
PATIENT

Have the patient stand on the scale with the back to the
measuring bar.

Ask the patient to stand straight. Lower the bar so that it
lightly touches the top of the patient's head.

Record the height in inches or centimeters in accordance
with local policy.

If the patient cannot stand, obtain an approximate height in
bed.

Have the patient lie on his back and stretch as much as
possible.

Place a mark on the bottom sheet at the patient's heel and
at the top of the patient's head.

Measure between these two marks on the taut bottom sheet.

Principles related to weighing the patient.

Weigh the patient before breakfast, at the same time each
day.

Use the same scale each time.

Ensure that the scale is properly balanced.

Weigh the patient in the same amount of clothing each day
(i.e., hospital gown or pajamas).

Have the patient void before weighing.

Avoid weighing any equipment attached to the patient such
as drainage bags or telemetry units. Hold the equipment while actually weighing the
patient.

A helpless patient may be weighed while lying down on a
litter scale. This scale is a sling-type device that looks like a suspended hammock. You
will need assistance to place the patient on the scale.

Record the patient's weight on the graphic sheet and in the
nurses' notes.

TEMPERATURE

Being human, we are homeothermic; we are warm-blooded and
maintain body temperature independently of our environment. Our body generates heat as it
burns food. It loses heat through the lungs (breathing), through the skin (sweating), and
in body discharges (urine, feces, vomitus, or blood). Body temperature is defined as the
measure of the heat inside the body: the balance between heat produced and heat lost.

TEMPERATURE REGULATION

Heat is produced through the metabolism of food
(chemically). Food is used as energy by muscles and glands to generate most of the heat in
the body. Heat is also gained (physically) from the environment.

During exercise, the muscles become active and the person
feels warm. Increasing muscular tone (shivering or gooseflesh) produces heat. The process
of digestion also increases body temperature.

When a person becomes angry or excited, the adrenal glands
become very active and the body warms as a result of the action of certain body chemicals
such as epinephrine.

The hypothalamus is the body's thermostat. It is located in
the central nervous system at the base of the brain. This heat-regulating center in the
brain senses any changes in the temperature of blood it receives and makes the appropriate
adjustments.

Heat loss occurs through the following:

Conduction--direct physical contact with an object.

Convection--when body heat warms surrounding air which rises
and is replaced by cooler air.

Evaporation--perspiration that is removed from the body
surface by change from a liquid to a vapor.

NORMAL BODY TEMPERATURE

A thermometer is placed in the patient's mouth to obtain an
oral temperature, in the anal canal to obtain a rectal temperature, and in an axilla
(armpit) to obtain an axillary temperature. Table 9-1 shows the average normal temperature
for well adults at these various body sites.

Table 9-1. Average, normal temperatures for
well adults.

ORAL

RECTAL

AXILLARY

98.6°F

99.5°F

97.7°F

37.0°C

37.5°C

36.5°C

Temperature is measured on the Fahrenheit (F) or the
Celsius (C) scale. The average, normal, oral temperature for an adult is 98.6 degrees
Fahrenheit or 37.0 degrees Celsius (old term: centigrade).

You can convert Fahrenheit to Celsius or vice versa.

To convert Fahrenheit to Celsius, subtract 32 and multiply
by 5/9.

To convert Celsius to Fahrenheit, multiply by 9/5 and add
32.

See Table 9-2 for a conversion chart.

Table 9-2. Celsius/Fahrenheit equivalent
temperature.

CELSIUS

FAHRENHEIT

34.0º C

35.0º C

36.0º C

36.5º C

37.0º C

37.5ºC

38.0º C

38.5º C

39.0º C

40.0º C

41.0º C

42.0º C

43.0º C

44.0º C

93.2º F

95.0º F

96.8º F

97.7ºF

98.6º F

99.5º F

100.4º F

101.3º F

102.2º F

104.0º F

105.5º F

107.6º F

C 109.4ºF

111.2º F

Body temperature may wary by 0.5ºF either way and still be
within normal limits.

FACTORS WHICH INFLUENCE NORMAL
BODY TEMPERATURE

Individual metabolism differs. An increase in the emotional
state of the patient may increase the temperature.

Body temperature is usually lowest in the morning and
highest in the late afternoon or evening.

Normal temperature for infants and children is usually
higher than the normal adult temperature. At birth, heat-regulating mechanisms are not
fully developed, so a marked fluctuation in body temperature may occur during the infant's
first year of life.

In some women, ovulation may be signaled by a slight drop
in body temperature 12 to 24 hours before a postovulation rise in temperature of about
0.4ºF to 0.8ºF.

TERMINOLOGY RELATED TO BODY
TEMPERATURE

Body temperature rises when heat production increases or
when heat loss decreases; both may be going on at the same time.

Everyone has a temperature; when the temperature is
elevated, then pyrexia or a fever is present. A fever is a symptom of some disorder. It
often accompanies illness; usually when the body is fighting an infection. An antipyretic
is a fever-reducing agent such as aspirin.

A temperature significantly below normal is called
hypothermia. Such temperatures often precede normal death. Hypothermia may occur as a
result of overexposure to winter elements or to cold water. Accidental hypothermia is life
threatening and must be treated immediately. Clinical hypothermia is often used to perform
surgical procedures because the lowered body temperature slows metabolism and thus
decreases the need for oxygen.

The patients most at risk of hypothermia are:

Postoperative patients.

Newborn infants exposed to room temperatures before their
body temperature has stabilized.

Elderly or debilitated patients.

TAKING THE TEMPERATURE

Regardless of the type of thermometer or measuring probe
used, certain rules apply.

Place the bulb or electronic probe so it is completely
surrounded by body tissues.

Remove the cover and discarded after the temperature is
taken. (Multi-use thermometers and temperature probes are covered when used.)
Prelubricated covers are used for rectal thermometers.

Record the temperature on the patient's graphic chart to the
even two tenths of a degree (unless the electronic thermometer is used). An electronic
thermometer is not calibrated with multiple numbers. It displays only the measured
temperature. Record the measured temperature.

TYPES OF THERMOMETERS

Clinical. The clinical
thermometer is a glass bulb containing mercury, with a stem in which the mercury can rise.
The stem has lines representing the measuring scale. It must read below normal range
before the temperature is taken. It should be rinsed in cold water to avoid distribution
of the mercury and breakage. If the thermometer is kept in a chemical solution, dry it
with a wipe in a twisting motion starting at the bulb. The clinical thermometer may be
oral or rectal.

The oral thermometer has a long, slender bulb. It may also
be used for axillary measurement.

The rectal thermometer has a blunt, short, fat bulb. It
should not be stored with the oral thermometers.

Figure 4-1. Clinical thermometers.

Electronic. The electronic
thermometer is portable and battery operated. It registers the temperature in 10 seconds
or less and displays it digitally. It must be fully charged to give an accurate reading,
so be sure the thermometer's base is plugged into an electrical outlet between uses.
Separate oral and rectal probes are supplied with each unit.

Disposable. The disposable is
single-use and has a sensor at the end of the shaft, which measures the temperature.

Patch. The thermometer patch
is a strip, which contains liquid crystals that change colors as the temperature changes.
It is usually placed on the forehead. The scale is adjusted to convert skin-surface
temperature to inner-body temperature. The calibration is not as detailed as that of a
glass thermometer.

TECHNOLOGY UPDATES

Electronic Forehead Thermometer

Click this image to see the device in
greater detail, learn more about the
specifications, and find an opportunity to purchase on
for your class or personal use.

Digital Thermometer

Click this image to see the instrument in
greater detail, learn more about the
specifications, and find an opportunity to purchase on
for your class or personal use.

METHODS OF OBTAINING A
TEMPERATURE

To obtain an oral temperature, place the thermometer in the
sublingual pocket and have the patient close his mouth around it. Instruct him not to bite
down. Leave the thermometer in place 3 to 4 minutes. If the patient has been eating,
drinking, smoking, brushing his teeth, or chewing gum within the past 15 minutes, wait at
least 15 minutes to take the temperature.

To obtain a rectal temperature, lubricate the bulb and the
area up to 1 inch above it. Use a lubricated probe cover with an electronic thermometer.
Turn the patient on his side, fold back the bedding and separate the buttocks so that you
can easily see the anal opening. Insert the thermometer approximately 1.5 inches into the
anus. Hold the thermometer in place for 3 to 4 minutes.

To obtain an axillary temperature, place the thermometer in
a dry axilla. Keep the arm close to the body to ensure contact with the bulb or probe for
8 to 10 minutes. Axillary is the method of choice for an infant.

Precautions.

Oral temperatures are contraindicated for an unconscious
patient, for an infant, or when the patient must breathe through the mouth.

The rectal method of obtaining the temperature is
contraindicated if the patient has diarrhea, rectal disease, or has recently had rectal
surgery.

PULSE

The pulse is the vibration of each wave of blood going
through the arteries as the heart beats. The pulse rate is usually equal to heart rate,
but may be lower if there is an obstruction of the artery or if the heart rhythm is weak
or irregular. You can feel it by placing your fingers over one of the large arteries that
lie close to the skin, especially if the artery runs across a bone and has very little
soft tissue around it.

There are eight common arterial pulse sites. (See figure
9-2).

Radial.

Temporal.

Carotid.

Apical (listening to the heart directly).

Brachial.

Femoral.

Popliteal.

Pedal (dorsalis pedis)

Figure 9-2. Arterial pulse sites.

The rate that the heart beats varies with the patient's
age, size, and weight. The normal rate for an adult is 60 to 80 beats per minute. Women
have a slightly higher average rate than men. The pulse of an infant ranges from 120 to
140 beats per minute. Rates for children vary according to the size and the age of the
child.

Activity affects the pulse rate. Exercise or heavy physical
work cause the heart to beat faster and the pulse rate to increase. Excitement, anger, and
fear increase the rate. Some drugs, such as caffeine, may also increase the pulse rate. If
the patient has a fever, the pulse rate increases in proportion to the body's temperature:
the pulse rate goes up about 10 beats for every 1ºF (0.56ºC). These conditions cause a
temporary increase in the heartbeat and pulse rate. The heartbeat and pulse rate that is
consistently above normal may be a sign of heart disease, heart failure, hemorrhage, an
overactive thyroid gland, or some other serious disturbance. The term for an abnormally
rapid heartbeat is tachycardia. When the heartbeat is continuously slow, below 60 per
minute, the condition is called bradycardia.

DESCRIBING THE PULSE

Pulse rate describes how often
the heart beats.

Pulse volume describes the force with which the heart
beats. The volume of the pulse varies with the volume of blood in the arteries, the
strength of the heart contractions, and the elasticity of the blood vessels. A normal
pulse can be felt with moderate pressure of the finger. When every beat is easily felt,
the pulse is described as strong. When greater pressure exerted by the finger cannot blot
out the pulse, it is called full or bounding. A pulse with little force is described as
weak or thready.

Pulse rhythm is the spacing of the heartbeats. When the
intervals between the beats are the same, the pulse is described as normal or regular.
When the pulse skips a beat occasionally, it is described as intermittent or irregular. A
pulse may be regular in rhythm but irregular in force, with every other beat being weak.
To obtain an accurate assessment of the heart rate, the pulse is counted by listening
directly to the heart (apical pulse).

FACTORS, WHICH AFFECT THE PULSE
RATE

The pulse rate is an indicator of how fast the heart beats.
The pulse rate is affected by several factors.

Age. A normal pulse for infants range from 90 to 170 and the
rate gradually decreases up to age 14 when it is equal to the normal adult pulse rate of
60 to 100.

Body Build and Size. A short, fat person may have a higher
rate than a tall, slender person.

Blood Pressure. As the blood pressure decreases, the pulse
will frequently increase.

Medications. Stimulants will increase the pulse rate;
depressants will decrease the pulse rate.

Exercise and Muscular Activity. An increase in pulse rate
will occur with increased activity to meet increased oxygen and nutrient demands. A
regular aerobic exercise program can lower the resting pulse. A person, who exercises a
great deal, such as an athlete, will develop bradycardia that is a normal, health
condition. The body slows the heartbeat to compensate for the greater volume of blood
pumped with each beat.

Food Intake. Digestion increases the pulse slightly.

Elevated Body Temperature. The pulse increases approximately
10 beats per minute for every 1 F (0.56º C) increase in body temperature. These
conditions cause a temporary increase in the heartbeat and pulse.

Emotional Status. Fear, anger, and anxiety will all increase
the pulse rate.

Pain. When the patient is in pain, the pulse rate will
increase.

MEASURING THE PULSE

Measuring a Radial Pulse.

Wash your hands to prevent the spread of infection.

Supporting the patient's arm and hand with the palm down,
press the first, second, and third finger of your dominant hand gently against the radius
bone until you feel the contraction and expansion of the artery with each heartbeat. Do
not use your thumb; it has a strong pulse of its own and you may be counting your pulse.

Count the pulsations for 30 seconds using a watch with a
second hand or digital display to time yourself. Multiply the count by 2 to determine the
rate for 1 minute. If the pulse is abnormal in any way, count for a full minute to get a
more accurate reading.

The pulse rate may also be determined by the electronic
vital signs monitor (see figure 4-3).

If there is any doubt about the rhythm or rate of the heart,
take an apical pulse.

Figure 4-3. Electronic vital signs monitor.

Measuring an Apical Pulse.

Warm the stethoscope in your hands. A cold stethoscope may
surprise the patient and alter the pulse rate.

Place the stethoscope at the apex (pointed end) of the
heart, in the left center of the chest, just below the nipple. The pulse can usually be
heard best at the apex.

Count the pulse for one full minute.

Measuring the Apical-Radial Pulse.

If the apical-radial (A-R) pulse is ordered by the
physician, two nurses carry out the procedure together.

Using the same watch, one nurse counts the patient's apical
pulse for 1 minute while the other nurse counts the radial pulse for 1 minute. One nurse
gives the signal to start counting, and both start at the same time. The two figures are
identified and charted (A-R pulse 76/72, for example). Normally, these two readings should
be the same. If there is a difference, it is called the pulse deficit.

NOTE: An apical pulse will never
be lower than the radial pulse.

RESPIRATION

Respiration is the process that brings oxygen into the body
and removes carbon dioxide waste. The exchange occurs in the lungs. Respiration occurs in
two phases: internal and external.

Internal respiration is the process by which oxygen is taken
from the bloodstream into the cell and carbon dioxide is removed from the cell to the
bloodstream.

External respiration refers to delivery of oxygen to the
lungs so that it can be taken into the bloodstream. External respiration (breathing) has
two components: Inspiration, the process of taking air into the lungs; and expiration,
expelling air from the lungs.

It is the rate of external respiration that is measured. The
normal adult rate is 14 to 20 breaths per minute. Women have a more rapid rate than men.
Newborns have a normal rate of about 40. Children have a normal rate of 25 to 30.

Respiration is controlled and regulated by the respiratory
center in the brain and by the amount of carbon dioxide in the blood. Respiration is
involuntary and automatic. You can control the action of your breathing to some extent,
but only for a limited time. If automatic breathing does not occur, a breathing disorder
exists.

BREATHING PATTERNS

Normal breathing is relaxed, effortless, and regular.

Rapid breathing is a rate above 20 breaths per minute,
associated with increased activity or a disease process. The medical term is tachypnea.

Slow breathing is a rate below 14. It may also be described
as shallow if the patient takes in and breathes out small amounts of air.

Dyspnea. Difficult breathing
describes when a person is making a definite effort to get more oxygen and get rid of
carbon dioxide. Dyspnea is the term for difficult breathing. Dyspnea is also the
term used for painful breathing, a subjective pattern, which must be stated by the
patient. Dyspnea may be a temporary condition, such as when a runner gasps at the end of a
race or when a person pants "to get his breathe" after climbing stairs. In some
diseases, such as pneumonia, emphysema, or some types of heart conditions, breathing
difficulty is more or less constant. Signs of breathing difficulties are: heaving of the
chest and the abdomen, and cyanosis (a bluish tinge in the skin).

Orthopnea is the term used if the
patient can breathe only when in an upright position.

Apnea is the absence of
respirations.

Cheyne-Stokes is the term for
cycles of breathing characterized by deep, rapid breaths for about 30 seconds, followed by
absence of respirations for 10 to 30 seconds. Cheyne-Stokes respirations constitute a
serious symptom and usually precedes death in cerebral hemorrhage, uremia, or heart
disease.

BLOOD PRESSURE

Two things determine the blood pressure: the rate and force
of the heartbeat and the ease with which the blood flows into the small branches of the
arteries. When the heart rate or force is increased by exertion or illness, blood pressure
increases. If the volume of blood within the circulatory system is reduced (as in
hemorrhage), and other factors remain the same, blood pressure decreases.

Blood pressure is the pressure exerted by the blood on the
walls of the blood vessels within the systemic arterial system. Normal systolic pressure
for a young adult is 100 to 120 mmHg (millimeters of mercury); diastolic pressure is about
80. Blood pressure increases gradually with age. Normal systolic pressure for a person 60
years of age is 130 to 140. Hypertension is blood pressure above normal limits (above
140/90); it is a sign of a circulatory problem. Hypotension is blood pressure below normal
limits (below 90/60) and may indicate shock. See table 4-3.

SYSTOLIC 100 to 140
mmHg

DIASTOLIC 60 to 90 mmHg

Table 4-3. Normal range of adult blood
pressure.

Systolic blood pressure is greatest. It is the pressure
against the wall of the blood vessels following ventricular contraction. Using the
auscultatory (listening) method, the systolic blood pressure is recorded at the highest
point at which two consecutive beats are heard (Korotkoff sounds).

Diastolic blood pressure is lowest. It is the pressure
against the blood vessels when the heart is relaxed before it begins to contract again.

The mean arterial pressure (MAP) denotes the average
pressure within the arteries. An electronic vital signs monitor can determine and display
an accurate average pressure or MAP.

Shock or other difficulty is usually indicated by a
systolic reading of 80 or less. A diastolic reading over 100 is usually considered
dangerously high.

MEASURING BLOOD PRESSURE

Blood pressure is usually measured indirectly using a
stethoscope and an instrument called the sphygmomanometer. The most common site is the arm
just above the antecubital area, using the brachial artery. Blood pressure may be measured
directly by means of a catheter or probe inserted into a blood vessel or the heart.

Direct Measurement.

One means of direct blood pressure measurement is to place a
special tube in a vein and monitor central venous pressure (CVP). Central venous pressure
may be used to determine fluid needs in shock, hemorrhage, or severe burns, to detect
pulmonary edema, and to determine the extent of circulatory overload.

Another method of direct blood pressure measurement is
internal or invasive monitoring. A large, flexible catheter, such as a Swan-Ganz catheter
measures pressures within the heart itself.

Indirect Measurement. The
sphygmomanometer (often called a blood pressure apparatus) includes a wide, cloth-covered
rubber cuff with two rubber tubes extending from it. One tube is connected to a bulb air
pump that has a valve, which can be opened or closed. The other tube is connected to a
glass cylinder containing mercury (mercury manometer) or to a dial (aneroid manometer),
which attaches to the arm wrap. You obtain the indirect blood pressure reading with the
manometer by listening to the heartbeat with a stethoscope.

Cleanse the stethoscope and earpiece with an alcohol wipe
before and after the procedure (unless you use your own stethoscope).

Have the patient lie down or rest comfortably in a chair
with the arm supported and the palm turned upward to expose the brachial artery on the
inside of the elbow.

Let the air out of the cuff. Wrap the cuff firmly around the
arm, just far enough above the elbow to leave the space over the brachial artery free, and
fasten the clip or Velcro closure.

Find the pulse in the artery and place the stethoscope over
the spot where you can feel the strongest pulsations.

Pump the manometer bulb to 20 mm above a possible systolic
pressure. Release the valve on the manometer bulb to gradually release air from the cuff.

Note the level on the mercury column or dial at which you
first hear a heartbeat. This is the systolic pressure.

Continue gradually releasing air from the cuff. Note the
point on the mercury column or dial at which the heartbeat cannot be heard, or at which
there is a distinct change in the sound. This is the diastolic pressure.

Release the remaining air from the cuff. Record the blood
pressure reading on the patient's chart by writing the systolic pressure above the
diastolic pressure. Use only even numbers.

Example: BP 120 or 120/80 80

Alternate Site for Measurement.
If it is impossible to measure the blood pressure in the arm, the leg is used. When blood
pressure is taken in the leg, the popliteal space (popliteal artery) is used, and the cuff
is applied above the knee. If you measure the blood pressure at any site other than the
arm, use the appropriate size cuff and indicate the site on the chart.

Electronic Blood Pressure Apparatus.
The cuff of the electronic blood pressure apparatus is applied and manipulated in
basically the same manner as with the mercury or aneroid manometer. The cuff is usually
inflated and deflated automatically. It is important to place the microphone under the
cuff so the arrow that indicates "artery" is in the correct location. Systolic
and diastolic pressures will be printed out on the screen within a few seconds.

FACTORS WHICH INFLUENCE BLOOD
PRESSURE VALUES

Age. Children normally have
lower blood pressure at birth (80/60), which gradually increases until the age of 18 when
it becomes equal to the normal adult pressure. Older adults frequently have higher blood
pressure due to a decrease in blood vessel elasticity.

Sex. Men have higher blood
pressure than women of the same age.

Body Build. Blood pressure is
usually elevated in an obese person.

Exercise. Muscular exertion
will temporarily elevate the blood pressure. A regular exercise program can eventually
decrease the resting blood pressure.

Disease States and Medication.
Some disease conditions and/or the medications influence the blood pressure.

PRINCIPLES RELATED TO OBTAINING
THE BLOOD PRESSURE

The patient's arm must be at the level of the heart. If the
arm is below the heart, false elevated pressures are obtained. If the arm is above the
heart, false lowered blood pressures are obtained.

The arm should be supported during the entire procedure to
prevent elevation due to muscle contractions used to maintain the position.

The cuff and stethoscope should be placed directly on the
skin. Light pressure should be applied when placing the stethoscope over the artery.

The cuff should be quickly deflated to zero, once the last
measurement is heard. Wait a minimum of 30 seconds before measuring the blood pressure
again.

THE GRAPHIC SHEET

a. A graphic sheet is maintained so that all vital sign
readings are easily accessible to members of the health care team. Each reading is
recorded as a dot in the proper space, with lines connecting the dots. Readings throughout
the patient's illness are indicated across the page in unbroken lines. The form used to
graphically record the patient's vital signs in a United States (US) Army hospital is SF
511, Clinical Record--Vital Signs Record.

b. Recording data.

(1) Enter the patient's identification data in the space at
the bottom of the form.

(2) Number the "Hospital Day" line of blocks with
the day of admission as one, and continue consecutively. Use the "Post-op Day"
line as applicable. The day of surgery is the operative day. The day following surgery is
noted as the first post-operative day.

(3) Label the day/hour blocks properly.

(4) Represent temperature by dots placed between the
columns and rows, and joined by straight lines. If the temperature is other than oral,
indicate so by (R) for rectal or (A) for axillary.

(5) Show pulse by use of a circle connected by straight
lines.

(6) Enter the respiration and blood pressure on the
indicated rows below the graphic portion.

(7) Record frequent blood pressure readings on the form's
graphic portion by entering an "X" between the columns and rows of dots, at
points equivalent to systolic and diastolic levels. Connect the two with a vertical solid
line.

(8) Use blank lines at the bottom of the sheet to record
special data such as the 24-hour total of the patient's intake and output.

CLOSING

Measuring and recording vital signs is not complicated;
however, these are important tasks because these measurements are indicators of functions,
which are necessary to sustain life. The patient's current vital signs can be compared
with those previously obtained or with normal values and changes in health can be detected
and treated quickly.